Towards omnidirectional, large scale, full polarization, and broadband practical invisibility cloaks: challenges and progress

Abstract

-Invisibility cloaks have experienced a tremendous development in the past few years, but the current technologies to convert the cloaks into practical applications are still facing numerous bottlenecks. In this paper, we provide the review of the challenges and recent progress in the invisibility cloaks from a practical perspective. In particular, the following key challenges such as non-extreme parameters, homogeneity, omnidirectivity, full polarization, large scale and broad band are addressed. We analyze the physical mechanisms behind the challenges and consequently evaluate the merits and defects of the recent solutions. We anticipate some compromises on the ideal cloaks are required in order to achieve practical invisibility cloaks in the future.

Transformation Laplacian metamaterials: recent advances in manipulating thermal and dc fields

“…More recently, calcite crystals have been employed to fabricate carpet cloaks based on linear transformation [17,18], and a ray-optics cloak has been experimentally demonstrated [19]. Readers may find more information in a recent review paper [20]. In addition to invisibility cloaking [8][9][10][11][12][13][14][15][16][17][18][19][20], TO theory has been applied to design a wide variety of optical devices, such as superlenses [21][22][23], hyperlenses [24,25], concentrators [26,27], rotators [28][29][30], artificial black holes [31,32], and bending waveguides [33,34].…”

“…Readers may find more information in a recent review paper [20]. In addition to invisibility cloaking [8][9][10][11][12][13][14][15][16][17][18][19][20], TO theory has been applied to design a wide variety of optical devices, such as superlenses [21][22][23], hyperlenses [24,25], concentrators [26,27], rotators [28][29][30], artificial black holes [31,32], and bending waveguides [33,34]. Beyond the optics/electromagnetics realm , this theoretical tool has been extended to matter waves [35], elastic waves [36,37], acoustic waves [38,39], magnetostatic fields [40][41][42][43], thermal conduction [44][45][46][47][48][49][50][51][52][53]…”

Signal manipulation through horn antennas loaded with metamaterial-inspired particles: A review

“…Artificial electromagnetic materials, metamaterials, and metasurfaces have revolutionized the design of microwave and optical components, allowing to obtain better performances with respect to conventional solutions [1][2][3][4][5][6][7][8] or novel functionalities [9][10][11][12][13][14]. In particular, in the last years, there was a strong interest in the use of metamaterials for performing the manipulation of the electromagnetic waves.…”

An experimental realization of cylindrical cloaking using dogbone metamaterials

“…Experimental realisations of electromagnetic cloaking at optical wavelengths are well known [23][24]. The different topological aspects and classifications of metamaterial cloaking are already available in review reports [25][26].…”